Variable current drive for isolated gate drivers

Abstract

A method for controlling a high-power drive device includes providing a current having a first predetermined current level to an output node during a first phase of a multi-phase turn-on process for the high-power drive device coupled to the output node. The method includes transitioning from the first phase to a second phase of the multi-phase turn-on process based on a first indication of a sensed voltage level on the output node during the first phase and a second indication of a time elapsed from a start of the first phase during the first phase. The method includes providing the current having a second predetermined current level to the output node during the second phase.

What is claimed is: 
     
         1 . A method for controlling a drive device, the method comprising:
 providing a current having a first predetermined current level to an output node during a first phase of a multi-phase turn-on process; and   transitioning from providing the current at the first predetermined current level to providing the current at a second predetermined current level based on a first indication of a sensed voltage level on the output node and a second indication of a time elapsed.   
     
     
         2 . The method as recited in  claim 1  further comprising providing the current having the first predetermined current level in response to a received control signal and in an absence of a fault condition. 
     
     
         3 . The method as recited in  claim 2  further comprising delaying providing the current having the first predetermined current level while providing the current having a third predetermined signal level. 
     
     
         4 . The method as recited in  claim 1  wherein the first predetermined current level is greater than the second predetermined current level. 
     
     
         5 . The method as recited in  claim 1  wherein transitioning from providing the current at the first predetermined current level to providing the current at the second predetermined current level is in response to the sensed voltage level exceeding a first threshold value or the time elapsed exceeding a second threshold value. 
     
     
         6 . The method as recited in  claim 5  wherein the first threshold value corresponds to a Miller plateau turn-on voltage of the drive device and the second threshold value corresponds to a time limit. 
     
     
         7 . The method as recited in  claim 1  further comprising converting a multi-bit digital control signal to the current having the first predetermined current level. 
     
     
         8 . The method as recited in  claim 7  wherein the transitioning comprises updating the multi-bit digital control signal from a first value corresponding to the first predetermined current level to a second value corresponding to the second predetermined current level. 
     
     
         9 . A driver product comprising:
 an output node;   a variable strength driver circuit coupled to the output node, the variable strength driver circuit being configured to provide a current to the output node, the current having a strength based on a control signal; and   a driver controller circuit configured to generate the control signal based on a received control signal, a first indication of a sensed voltage level on the output node, and a second indication of a time elapsed.   
     
     
         10 . The driver product as recited in  claim 9  further comprising a timer circuit configured to generate the second indication. 
     
     
         11 . The driver product as recited in  claim 9  wherein the driver controller circuit is further responsive to a fault indication signal. 
     
     
         12 . The driver product as recited in  claim 9  wherein the variable strength driver circuit comprises:
 a first current digital-to-analog converter circuit configured to generate a turn-on voltage, the first current digital-to-analog converter circuit including a first current mirror with a fixed input stage and a first selectively configurable output stage and a first reservoir capacitor coupled in parallel with a first diode-coupled input device of the fixed input stage; and 
 a second current digital-to-analog converter circuit configured to generate a turn-off voltage, the second current digital-to-analog converter circuit including a second current mirror with a second fixed input stage and a second selectively configurable output stage and a second reservoir capacitor coupled in parallel with a second diode-coupled input device of the fixed input stage. 
 
     
     
         13 . The driver product as recited in  claim 9  further comprising a storage element configured to store a profile of a multi-phase turn-on process for generating the control signal. 
     
     
         14 . The driver product as recited in  claim 13  wherein the profile includes a first control value corresponding to a first target current level and a second control value corresponding to a second target current level, the first target current level greater than the second target current level. 
     
     
         15 . The driver product as recited in  claim 13  wherein the profile includes a first threshold value corresponding to a Miller plateau turn-on voltage of a drive device coupled to the driver product. 
     
     
         16 . The driver product as recited in  claim 13  wherein the profile includes a second threshold value corresponding to a time limit for providing a first current level. 
     
     
         17 . The driver product as recited in  claim 9  further comprising:
 a first integrated circuit die and a second integrated circuit die that implement low-voltage control and isolation; 
 a third integrated circuit die including the output node, the variable strength driver circuit, and the driver controller circuit; and 
 a package housing the first integrated circuit die, the second integrated circuit die, and the third integrated circuit die. 
 
     
     
         18 . The driver product as recited in  claim 9  further comprising:
 a first integrated circuit die and a second integrated circuit die that implement low-voltage control and isolation; 
 a third integrated circuit die including the output node, the variable strength driver circuit, and the driver controller circuit; 
 a first package housing the first integrated circuit die and the second integrated circuit die; and 
 a second package housing the third integrated circuit die, the first package including standard power-dissipation features and the second package including enhanced power-dissipation features. 
 
     
     
         19 . The driver product as recited in  claim 9  further comprising:
 a first integrated circuit die and a second integrated circuit die implementing low-voltage control and isolation; 
 a third integrated circuit die including the output node, the variable strength driver circuit, and the driver controller circuit; 
 a fourth integrated circuit die comprising a second output node, a second variable strength driver circuit, and a second indicator circuit, the output node being coupled to a drive device of the driver product and the second output node being coupled to the drive device or a second drive device; 
 a first package housing the first integrated circuit die and the second integrated circuit die, the first package including standard power-dissipation features; 
 a second package housing the third integrated circuit die; and 
 a third package housing the fourth integrated circuit die, the second package and the third package each including enhanced power-dissipation features. 
 
     
     
         20 . A driver product comprising:
 a first integrated circuit die and a second integrated circuit die implementing low-voltage control and isolation;   a third integrated circuit die including a variable strength driver circuit configured to provide a current to an output node of the third integrated circuit die, the current having a strength based on a received control signal, a first indication of a sensed voltage level on the output node, and a second indication of a time elapsed;   a fourth integrated circuit die comprising a second output node, a second variable strength driver circuit, and a second indicator circuit, the output node configured to be coupled to a drive device and the second output node configured to be coupled to the drive device or to a second drive device;   a first package housing the first integrated circuit die and the second integrated circuit die, the first package including standard power-dissipation features;   a second package housing the third integrated circuit die; and   a third package housing the fourth integrated circuit die, the second package and the third package each including enhanced power-dissipation features.